Let's say you're creating a new content type in Drupal 7. Maybe you want include an embedded MP3 player using the Media module. Easy, right? Mmm...sort of.
I won't bore you here with the process of installing and configuring the module. Others have done that already (though curiously not the module maintainers). What I will do hopefully is save you a little frustration and time.
You see, lot of technically gifted people are lousy writers. Case in point: look at the image below. When I read "Input a url or embed code from one of the listed providers." on the form, I took it to mean that I could only link to YouTube videos. What I wanted to do was have an embedded media player point to an offsite file. That appeared to be against the rules, so I spent the next hour scouring the Googles for a way to do it. Then, out of frustration, I just pasted in the URL of a dropbox file. It worked. You can see it here. Happy Drupaling!